The invention relates to a bearing material displaying a low coefficient of friction and low wear at relatively high load, relatively high speed and relatively high temperature.
Such materials are applied, for instance, as "dry" bearing material, i.e., bearing material requiring no additional lubricant on account of the low coefficient of friction, .mu.. A potential application particularly is in plain bearings. The principal requirement of such materials is that, at the speeds, loads and temperatures involved, they always display a sufficiently low coefficient of friction and have a long service life.
A known example of such material is polytetrafluoroethylene (PFTE) which, applied in bearings involving very low speeds, such as in bearings supporting bridges, displays a .mu. of 0.02-0.05. In the majority of applications in bearings, the .mu. is higher, however, viz. 0.1-0.2. Generally, the .mu. of PTFE increases along with increasing speeds and decreases along with decreasing loads. As the transition temperature of PTFE is 327.degree. C., particularly at high speeds and therefore at high temperatures, the material is not suitable as bearing material. Furthermore, the wear properties of PTFE measured, for example, with the aid of a "Falex tester" appear to be unfavorable and it is found that at pressures beyond 70 kg/cm.sup.2, PTFE begins to deform, indicating that the rigidity of the material is insufficient at such pressures. The properties of PTFE as bearing material are described in the book "Lubrication and Lubricants", edited by E. R. Braithwaite, on pp. 412 et seq.